It was well known he did this, though I've never seen any specific ways he set out to accomplish this. My guess is it wasn't intentional to start, but something he noticed and refined over the years via practice; Harry himself disclosed very little about how he practiced, but he was known to practice all the time.

Houdini's famed strength indirectly also lead to his death: https://en.wikipedia.org/wiki/Harry_Houdini#Death

Strength, and hubris.

Hubris? Sounds like he was assaulted.

The 3rd-to-last and 2nd-to-last paragraphs of the section do seem to suggest some hubris; not seeking medical attention despite constant pain and fever, ignoring medical advice that he needed immediate surgery and continuing to perform.

I don't think the quality of medical was quite was it now, even after WWI. For example, remember that antibiotics hadn't been discovered yet.